In iperf experiments running linux as the Tx side (TCP client) with
10 threads results in a severe performance drop when TSO is disabled,
indicating a weakness in the software that can be avoided by using
the scalable IOMMU arena DMA allocation.
Baseline numbers before this patch:
with default settings (TSO enabled) : 9-9.5 Gbps
Disable TSO using ethtool- drops badly: 2-3 Gbps.
After this patch, iperf client with 10 threads, can give a
throughput of at least 8.5 Gbps, even when TSO is disabled.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
I applied the wrong version of this patch series, V4 instead
of V10, due to a patchwork bundling snafu.
Signed-off-by: David S. Miller <davem@davemloft.net>
In iperf experiments running linux as the Tx side (TCP client) with
10 threads results in a severe performance drop when TSO is disabled,
indicating a weakness in the software that can be avoided by using
the scalable IOMMU arena DMA allocation.
Baseline numbers before this patch:
with default settings (TSO enabled) : 9-9.5 Gbps
Disable TSO using ethtool- drops badly: 2-3 Gbps.
After this patch, iperf client with 10 threads, can give a
throughput of at least 8.5 Gbps, even when TSO is disabled.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &__get_cpu_var(x). This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.
Other use cases are for storing and retrieving data from the current
processors percpu area. __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.
__get_cpu_var() is defined as :
#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))
__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.
this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.
This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset. Thereby address calculations are avoided and less registers
are used when code is generated.
At the end of the patch set all uses of __get_cpu_var have been removed so
the macro is removed too.
The patch set includes passes over all arches as well. Once these operations
are used throughout then specialized macros can be defined in non -x86
arches as well in order to optimize per cpu access by f.e. using a global
register that may be set to the per cpu base.
Transformations done to __get_cpu_var()
1. Determine the address of the percpu instance of the current processor.
DEFINE_PER_CPU(int, y);
int *x = &__get_cpu_var(y);
Converts to
int *x = this_cpu_ptr(&y);
2. Same as #1 but this time an array structure is involved.
DEFINE_PER_CPU(int, y[20]);
int *x = __get_cpu_var(y);
Converts to
int *x = this_cpu_ptr(y);
3. Retrieve the content of the current processors instance of a per cpu
variable.
DEFINE_PER_CPU(int, y);
int x = __get_cpu_var(y)
Converts to
int x = __this_cpu_read(y);
4. Retrieve the content of a percpu struct
DEFINE_PER_CPU(struct mystruct, y);
struct mystruct x = __get_cpu_var(y);
Converts to
memcpy(&x, this_cpu_ptr(&y), sizeof(x));
5. Assignment to a per cpu variable
DEFINE_PER_CPU(int, y)
__get_cpu_var(y) = x;
Converts to
__this_cpu_write(y, x);
6. Increment/Decrement etc of a per cpu variable
DEFINE_PER_CPU(int, y);
__get_cpu_var(y)++
Converts to
__this_cpu_inc(y)
Cc: sparclinux@vger.kernel.org
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
CONFIG_HOTPLUG is going away as an option. As a result, the __dev*
markings need to be removed.
This change removes the use of __devinit, __devexit_p, __devinitdata,
and __devexit from these drivers.
Based on patches originally written by Bill Pemberton, but redone by me
in order to handle some of the coding style issues better, by hand.
Cc: Bill Pemberton <wfp5p@virginia.edu>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
removes unnecessary semicolon
Found by Coccinelle: http://coccinelle.lip6.fr/
Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Adapt core SPARC architecture code for dma_map_ops changes: replace
alloc/free_coherent with generic alloc/free methods.
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David S. Miller <davem@davemloft.net>
This silently was working for many years and stopped working on
Niagara-T3 machines.
We need to set the MSIQ to VALID before we can set it's state to IDLE.
On Niagara-T3, setting the state to IDLE first was causing HV_EINVAL
errors. The hypervisor documentation says, rather ambiguously, that
the MSIQ must be "initialized" before one can set the state.
I previously understood this to mean merely that a successful setconf()
operation has been performed on the MSIQ, which we have done at this
point. But it seems to also mean that it has been set VALID too.
Signed-off-by: David S. Miller <davem@davemloft.net>
These files are only exporting symbols, so they don't need
the full module.h header file. Previously they were getting
access to EXPORT_SYMBOL implicitly via overuse of module.h
from within other .h files, but that is being cleaned up.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Fix all of the problems spotted by CONFIG_DEBUG_SECTION_MISMATCH under
arch/sparc during a 64-bit defconfig build.
They fall into two categorites:
1) of_device_id is marked as __initdata, and we can never do this
since these objects sit in the device core data structures way
past boot. So even if a driver will never be reloaded, we have
to keep the device ID table around.
Mark such cases const instead.
2) The bootmem alloc/free handling code in mdesc.c was not fully
marked __init as it should be, thus generating a reference
to free_bootmem_late() (which is __init) from non-__init code.
Signed-off-by: David S. Miller <davem@davemloft.net>
Most of the warnings emitted (we fail arch/sparc file
builds with -Werror) were legitimate but harmless, however
one case (n2_pcr_write) was a genuine bug.
Based almost entirely upon a patch by Sam Ravnborg.
Reported-by: Dennis Gilmore <dennis@ausil.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
The generic irq support uses the term 'irq' for the
allocated irq number.
Fix it so sparc64 use the same term for an irq as the
generic irq support does.
For a naive reader this is less confusing.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Get rid of old users of of_platform_driver in arch/sparc. Most
of_platform_driver users can be converted to use the platform_bus
directly.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
of_device is just a #define alias to platform_device. This patch
replaces all references to it with platform_device.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: David S. Miller <davem@davemloft.net>
Both of_bus_type and of_platform_bus_type are just #define aliases
for the platform bus. This patch removes all references to them and
switches to the of_register_platform_driver()/of_unregister_platform_driver()
API for registering.
Subsequent patches will convert each user of of_register_platform_driver()
into plain platform_drivers without the of_platform_driver shim. At which
point the of_register_platform_driver()/of_unregister_platform_driver()
functions can be removed.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: David S. Miller <davem@davemloft.net>
.name, .match_table and .owner are duplicated in both of_platform_driver
and device_driver. This patch is a removes the extra copies from struct
of_platform_driver and converts all users to the device_driver members.
This patch is a pretty mechanical change. The usage model doesn't change
and if any drivers have been missed, or if anything has been fixed up
incorrectly, then it will fail with a compile time error, and the fixup
will be trivial. This patch looks big and scary because it touches so
many files, but it should be pretty safe.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Sean MacLennan <smaclennan@pikatech.com>
The following structure elements duplicate the information in
'struct device.of_node' and so are being eliminated. This patch
makes all readers of these elements use device.of_node instead.
(struct of_device *)->node
(struct dev_archdata *)->prom_node (sparc)
(struct dev_archdata *)->of_node (powerpc & microblaze)
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Now sparc uses include/asm-generic/dma-mapping-common.h.
pci_sun4v.c doesn't need to have no-op
dma_4v_sync_single_for_cpu and dma_4v_sync_sg_for_cpu
(dma-mapping-common.h does nothing if sync_{single|sg}_for_cpu
hook is not defined). So we can remove them safely.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Tested-by: Robert Reif <reif@earthlink.net>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: tony.luck@intel.com
Cc: fenghua.yu@intel.com
LKML-Reference: <1249872797-1314-6-git-send-email-fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch converts dma_map_single and dma_unmap_single to use
map_page and unmap_page respectively and removes unnecessary
map_single and unmap_single. map_page can be used to implement
map_single but the opposite is impossible. Having only dma_map_page in
struct dma_ops is enough.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Tested-by: Robert Reif <reif@earthlink.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Andrew Morton wrote:
People keep on doing
printk("%llu", some_u64);
testing it only on x86_64 and this generates a warning storm on
powerpc, sparc64, etc. Because they use `long', not `long long'.
Quite a few 64-bit architectures are using `long' for their
s64/u64 types. We should convert them all to `long long'.
Update types.h so we use unsigned long long for u64 and
fix all warnings in sparc64 code.
Tested with an allnoconfig, defconfig and allmodconfig builds.
This patch introduces additional warnings in several drivers.
These will be dealt with in separate patches.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
o Move all files from sparc64/kernel/ to sparc/kernel
- rename as appropriate
o Update sparc/Makefile to the changes
o Update sparc/kernel/Makefile to include the sparc64 files
NOTE: This commit changes link order on sparc64!
Link order had to change for either of sparc32 and sparc64.
And assuming sparc64 see more testing than sparc32 change link
order on sparc64 where issues will be caught faster.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
